Hoisting apparatus.



PATENTED AUG. 29, 1905.

V. R. & B. H. BROWNING. HOISTING APPARATUS.

APPLICATION FILED 0G'1.4,190l.

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No. 798,494. PATENTED AUG. 29, 1905.

v V. R. & E. H. BROWNING.

HOISTING APPARATUS.

APPLICATION FILED 00T.4, 1901.

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HOISTING APPARATUS.

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, UNITED STATES OFFICE.

VICTOR R. BROINNING AND EARL H. BROlVNINUr, OF CLEVELAND, OHIO.

HOISTING APPARATUS.

Specification of Letters Patent.

Patented Aug. 29, 1905.

To (all whom, it may concern:

Be it known that we, VIo'roR R. BROWNING and EARL 1-1. BROWNING,citizens of the United States, residing at Cleveland, in the county ofCuyahoga and State of Ohio, have invented a new and useful Improvementin Hoisting Apparatus, of which the following is a specification.

This invention relates in general to hoisting apparatus, and has moreparticularly reference to the means employed for dispensing with theauxiliary hoist in devices of this kind, said means consisting of adifferential mechanism, which is connected with the motor in such a waythat by throwing in the low speed additional lifting force may besecured, or by throwing in the high-speed device a more rapid liftingmovement with consequent loss of lifting force may be obtained.

Our invention has for its objects, therefore, the production of a devicewhereby the speed of lifting can be conveniently controlled withoutimpairing the efiicieney of the motor, whereby greater compactness andlightness in structure can be secured, and whereby the transverseswinging movement of the load, which always accompanies devices of thischaracter as heretofore made, may be avoided.

Numerous other features of construction embodying distinct advances inthe art are also employed, and these will be more fully set forth in thefollowing specification and in the claims appended thereto.

In the drawings forming part of this application, Figure 1 shows alongitudinal section through our improved hoisting apparatus, taken in avertical plane through the center. Fig. 2 shows a view looking towardthe righthand end of Fig. 1, a portion of the differential gearmechanism beingshown in section, said section being taken on the line 22 of Fig. 1. This figure also shows in diagram the electric controlleror switch for regulating the strength of current in the electric brakeand the magnetic clutch for the differential gear mechanism. Fig. 3shows a portion of an overhead traveling crane having our improvedhoisting device in the trolley therefor. Fig. 4 shows a sectional viewthrough the safety lowering device. Fig. 5 shows a modified form ofcontacting surfaces for the magnetic clutch. and Figs. 6 and 7 showdifferent means for driving the hoisting-drum in which engines ratherthan an electric motor are employed.

Similar reference characters designate corresponding parts throughoutthe several views of the drawings.

Heretofore, as far as we are aware, it has been necessary, especially inoverhead travelingcranes,to provide two independent hoisting devices tooperate on light and heavy loads. To operate these cranes economically,it is desirable that the speed of hoisting should be proportioned to theweight of the load, otherwise a light load would require as long a timefor handling as would a much heavier one. It has not been practicable tochange the rate of hoisting to a suiiicient degree with one hoistingdevice to satisfy the requirements for light and heavy loads, however,without greatly sacrificing the efliciency of the motors employed, itbeing understood that in order to get the greatest eiiiciency out of amotor it should be run at the speed for which it is designed.

In order to avoid the expense and the necessity of employing both a mainand an auxiliary hoist, we have devised a differential gear mechanism,which is connected to the shaft of our motor, by means of which we canat will convert the single hoisting device from a main hoist for heavyloads to an auxiliary hoist for light loads. Furthermore, we haverendered the device very light and compact by using the hoisting-drum asthe field-magnet for the hoisting-motor. WVith these features ofconstruction we also combine certain safety appliances, so that ourhoisting mechanism is rendered entirely safe and reliable.

In the drawings, 1, Fig. 3, shows a portion of the bridge of an overheadtraveling crane, since it is in connection with this class of hoistingmechanism that we have chosen to show our device applied. It will beunderstood, however, that our differential mechanism, as well as ourhoisting-drum fieldmagnet, is applicable to any sort of hoisting devicewhere different speeds of hoist are required. 2 shows one of therunway-tracks upon which this crane is adapted to travel. Upon its uppersurface, preferably, we provide the crane body with runway tracks 3,(shown in Figs. 2 and 3 of the d rawings,) upon which run thetrack-wheels L of the trolley. These track-wheels are secured to shafts5, which are journaled to the lower side of the frame, the longitudinalmembers of which are shown at 6. Rising above these longitudinalmembers, preferably over the axles 5, are the end frames 7 and 8, theseframes being broad at their bases and converging toward their tops.

In order to economize weight and space and expense, we cause thehoisting-drum, which is shown at 9, to serve not only as a drum forhoisting, but as the field-magnets for our motor. As it is necessary forthe drum to turn, and also for the armature to rotate within the same,it is necessary to form the journals of the armature-shaf t within thejournals of the hoisting-drum. This, as will readily be seen, willrequire large trunnions or journals for the hoisting-drum, whichjournals are placed in the end frame-pieces 7 and 8, as shown at 10 inFig. 1. In order to overcome the friction in these journals as far aspossible, we provide the bearings with nests of rollers, which are shownat 11.

The motor-shaft, which is indicated at 12, passes through the center ofthe trunnions for the drum and extends for some distance beyond the endframes 7 and 8. Keyed to the shaft 12 near its right-hand end, as seenin Fig. 1, is a pinion 13. Also mounted to turn upon this end of theshaft or upon bushings carried by the same is a trunnionframe let, whichconsists of two dislvshaped side plates, which for the purpose of givingthe required strength are cast with suitable connecting portions (shownat 15 in Fig. That face of the disk-shaped side plate which is next tothe frame-piece 8 of the trolley is provided with a pinion 16, whichmeshes with a large gear-wheel 1?. This gearwheel is keyed to alongitudinal shaft 18. which is journaled in the side frames 7 and 8above the motor-shaft 12, and which carries near its end opposite thegear 17 a pinion 19. This pinion, which is driven with the shaft, meshes;/with a large annular gear 20, which is keyed to the end of theho1st1ngdrum 9. From this description it will be seen that when thetrunnion-frame 1a, 'with its pinion 16, is turned motion will betransmitted through the gears 17, 1t), and 20 to the hoisting-drum 9.

Journaled within the trunnion-frame 1st are a number of plan et-gears21, all of which mesh with the pinion 13, which, as has been stated, iskeyed to the shaft 12. \Vhen the shaft is turned, therefore. and theseplanet-gears are permitted to rotate, they will turn on their axles in adirection opposite to that of the pinion 13. The disk-like plates of thetrunnion-frame 1 1 are each provided on their outer sides with hub-likeextensions, upon which is trnnnioned a frame which carries an internalgear 22, which is in line and in mesh with the planet-gears 21. Thisframe is composed of two main pieces 23 and 21, which are suitablysecured togefher so as to form a boxlike covering for the various gears.\Vere the internal gear 22 and its supporting framepiece 23 permitted todo so they would turn freely upon theirtrunnions if the motor-shaft 12were rotated and no power would be transmitted through the train ofgears extending to the hoisting-drums. \Vhen, however, this frame andits internal gear are held stationary While the motor-shaft with itspinion 13 is rotated in either direction, the planet-gearing will becaused to travel about within the internal gear 22 in the samedirection, and will in this way cause the pinion 16 to be rotatcd at aspeed which is very much slower than the speed of the pinion 13, theratio of said speeds depending upon the ratio of the diameters of thegears-13 and 22. In order to hold the frame-piece 23 and its internalgear from rotation, we groove its outer circumference forthe receptionof a brake-strap 25, which passes around the same and has its oppositeends connected to the ends of a bellcrank 26. As has been stated, whenthe frame 23 and its internal gear are held as described theplanet-gears will travel slowly about within the same, and as they aresecurely journaled in the trunnion-frame 14 the frame and the pinion 16will be driven slowly, which will also, through its train of gears andshaft 18, drive the hoisting-(.lrum 9 at a slow speed. Therefore when itis desired to lift a heavy load the brake-strap 25 should be caused toengage tightly with the surface of the framepiece 23, which will holdthe internal gear 22 from rotation. There are times, however, when it isvery desirable to rotate the hoisting-drum at a much greater speed. andfor this reason it should be made possible to turn the pinion 16 athigher rates of speed, the highest possible rate for the n'ieclianisnishown being that at which the pinion 13 or the motor-shaft 12 is driven.For purposes of description we will first assume that we desire tochange the slow speeds for heavy loads, which is secured as abovedescribed, to the highest rate of speed that is, to the speed which isattained when the pinion 16 is driven with the shaft. As has beenstated, when the frame 23 and its internal gear are held stationary theframe 1 1 rotates within the same. If new the trunnion-frame and theframe 23 were locked together, so that they would be compelled to rotateas a single piece, and the brake-strap 25 were loosened, so that theycould so rotate, the pinion 13, planet-gears 21, internal gear 22, andpinion 16 would all be rigidly locked and would all rotate together asone gear. (.onsequently when the motor-shaft was turned the frame 23 andall the gears which it contains would be driven with the same and motionwould be transmitted through the train of gears to the hoisting-drum,driving the same at a very much higher speed than when the trunnionframewas permitted to move. Various means may be employed for locking thetrunnionframe and the frame 23 together; but we prefer to use theelectric clutch i'neelumisin, which is shown in Fig. 1. The fran1e-iiece23, which is made of iron, has a circular recess extending about andat some little distance from the hub of the trunnionframe, upon which itis mounted. Vithin this recess we place a coil of wire 26 and secure thesame in place in the recess by means of an annular soft-iron plate 27.The ends of this coil are drawn through a hole which is made in the part23, and thence through a hole through the same frame outside theinternal gear 22 to rings 28, which are carried in the outer side of theframe-piece 2 L These rings, it will be understood, extend entirelyabout the motor-shaft, so that they may be constantly engaged by brushes29, which are carried by a bracket 30, projecting from themain.frame-piece 8. In Fig. 2 we have shown at 31 a conventional form ofcontroller or switch-box, which is placed in the electric circuitrunning to the brushes 29 and by means of which the strength of currentcan be regulated or entirely cut oil". When the current is turnedthrough the magnet-coils 26', the frame-piece 23 is converted into anelectromagnet, the lines of force passing through that portion which isembraced by the coil, thence across the airgap between the frame-piece23 and the trunnion-frame 14 into the trunnion-frame, thence across theair-gap again, thence through the frame-piece 23 outside the coil, andthence through the plate 27, thus completing the circuit. As is wellunderstood, the trunnionframe 14 will be very strongly attracted by andwill be drawn up to the frame-piece 23, to which it will adhere soclosely as to prevent slippage between the contacting surfaces. In viewof the previous description it will now be understood that as soon asthe current is thrown into the coils 26, as described, thetrunnion-frame will be drawn into contact with the frame-piece 23, andthe entire series of gears, including the pinion 16, will be driven asone piece with the. motor-shaft, which will greatly increase the speedof the hoistingdrum. The pinions 13 and 16 and also the internal gear 22are provided with elongated teeth, so as to permit the trunnion-frame,with its planet-gearing and pinion 16, to be drawn over and still remainperfectly in mesh.

In order to permit the frame-piece 23 to rotate, as above described, itis necessary to loosen the brake-strap 25, which normally holds itstationary. As has been stated, this brake-strap is secured at itsopposite ends to the bellcrank 26. This bell-crank is pivoted to abracket 32, which projects from the main piece 8. Secured to thisbell-crank and rigid therewith is a lever-arm 33, which projectsforwardly below the frame-piece 23 and carries at its forward endaweight 341. As long as this weight is permitted to hold down -the endof this lever the brake-strap will be held tightly about thecircumference of the frame-piece 23, thus holding the same fromrotation. Before it can be permitted to rotate, therefore, thisbrake-strap must be loosened, and in order to secure this result weprovide an electromagnet 35, which is secured to a bracket 36,projecting from the main frame-piece 8. This magnet, which is ofpeculiar construction, in order that it may attract its plunger 37 withas great force as possible is composed of an outer soft-iron cylindricalshell, within which is placed the magnet-coils. Projecting from the topof the magnet at the center between the coils is a soft-iron boss or hub33, said boss being provided with a conical countersink to lit the upperend of the plunger 37. This plunger forms a portion of the armature, themain portion 39 of which is jointedly secured to the lever 33. Thisstructure causes the lines of force to pass upwardly through theplunger, and thence across the gap between the conical end thereof andthe countersink in the magnet. This gives the magnet the effect of asolenoid, so that when the lever 33 is in its lowermost position themagnet will have sufficient strength to draw in the plunger and lift thelever. The armature 39 will also be attracted by the lower portion ofthe shell, which will securely hold the lever in its position with thebrake-strap released. As will be understood, it is necessary to releasethis brake-strap to free the frame-piece 23 at the same time that thecurrent is thrown into the friction-clutch coils 26, and for this reasonthe two magnetcoils are placed in series, the same current passingaround both. \Vhenever, therefore, the current is turned into thiscircuit, it will result in releasing the frame-piece 23 from thebrake-strap at the same time that it secures it to the trunnionframe 14.\Vhen, therefore, it is desired to change the hoist from a slow to ahigh speed, all that is necessary is to turn the switch 31 and throw thecurrent through these two magnet-coils.

Thus far we have described our device as adapted to only twospeeds-viz., the slow speed for heavy hoisting and the rapid speed whenthe gears are firmly locked together and rotate with the shaft. Thereare loads, however, which are too heavy for this very high speed and toolight to make it economical to use the very slow speed, the ratio ofthese speeds under most conditions being about four to one, although anyother ratio maybe employed. It is desirable, therefore, to provide astructure whereby any required intermediate speed may be secured. Thestructure already described, however, is adapted to this end, for thereason that the surfaces between the brake-strap and the frame-piece 23and between this piece and the trunnionframe are smooth and may bepermitted to slip when in contact. Now the ease with which thesesurfaces may slide upon each other will depend upon the strength of thecurrent passing through the magnet 35 and the friction-brake coils 26.Thus when the lever of the switch 31 is moved to the first segment showna weak current will pass, which will loosen the brake-strap onlyslightlyand will also create only a small amount of friction between thetrunnion-frame and the frame-piece 23. Consequently the framepiece 23will move very slowly,while the movement between the trunnion-frame andthe frame-piece will be but slightly diminished, so that the rate ofhoisting will not be very greatlyincreased. Vhemhowever,theswitcl leveris moved to the farthest segment and the current is thrown on in fullstrength, the trunnion-frame will be securely held to the frame-pieceand the brake-strap entirely released, so that the maximum rate ofhoisting willbe secured. It will be understood that when theswitch-lever is placed upon any of the intermediate segments thestrength of current will be again changed, and the amount of slippage inthe brake and the frictionclutch will also vary, so that the speed ofhoisting will be changed. In this way any speed desired within the twofixed limits first described may be secured.

From the foregoing description it will be seen that the pinion 16 isalways driven in the same direction as the pinion 13, whether it islocked to turn therewith by the frictionclutch device or is driventherefrom through the intermediate planetary gearing. This will causethe drum 9 and armature 4:7 to always turn in the same direction. Thiswe regard as a valuable invention, as it enables a motor which isdesigned for a comparatively low speed with reference to itsmagnet-fields to attain a high speed with reference to outside objects,said latter speed being the summation of the former speed and the speedof rotation of the field-magnets. Thus by gearing up the field-magnets,so that they rotate at a higher rate of speed, the same armature willrotate with that much greater speed withreference to outside objects. Itwill be understood also that if a slow armature speed with reference tooutside objects is desired this may be secured by interposing an idlerin the train of driving-gears, which will rotate the field in theopposite direction.

\Vhile we have never had any difficulty and believe that no difficultywill ever be experienced in using smooth cont-acting surfaces betweenthe trunnion-frame and the framepiece 23, at the same time if it shouldbe found that a suflicient amount of friction cannot be produced betweenthese surfaces to lift the required loads they may be corrugated, asshown in the detailed view at Fig. 5, in which 1 .2 represents thetrunnion-frame and 23 the framepiece, as before. When constructed inthis manner, it will be impossible for these surfaces to slip unlessthey cam themselves apart, and the pull of the electromagnet will besufficient to prevent any such action. As will be evident, however, thisconstruction makes only the two extreme speeds of hoist possible, andfor this reason we prefer not to use the corrugated surface except underconditions when it becomes absolutely essential.

As has been stated, the drum 9 is caused to serve as the field-magnetfor the electric motor. \Vith this end in view we form in the innersurface of the drum a suitable number of inwardly-projecting pole-pieces10, about which are placed spools of magnet-wire, as shown at 41. Thecurrent for the motor onters, say, through the wire a2, thence through amagnetic clutch, which will be hereinafter described, from which itpasses to the brush 43 and from thence to the ring 4st, which is mountedupon the end of the drum 9. From this ring the current is led throughthe wire 45 and brush 16 to the armature 17. After passing through thearmature the current is led by way of the brush 48 to the field-magnetcoils 41 and thence to the ring 49 on the end of the drum, from which itthen returns through the brush 50 and wire 51 to its originalstarting-point. it will thus be seen that the armature and field-coilsare in series, although they may obviously be placed in parallel, ifpreferred. In order to stop the motor as quickly as possible without asudden shock,

we key or otherwise secure to the end of the motor-shaft 12 a disk 52,the same being held in place by a nut 53. Loosely mounted upon the shaft12, between the disk 52 and the frame piece 7, is a cylindrical piece ofiron 54:, which constitutes one member of the magnetic clutch. On thatsurface of the clutch member 54 which is turned toward the armature :7we form a circular groove, in which are placed the magnet-coils 55. Thecurrentfor the motor is led through these coils, which are connected upin series with the armature and fieldmagnets ll. ln order to prevent theclutch member from turning with the shaft 12, we provide the same with aprojection 56, which is adapted to engage with statioi'iary lingers 57,which project, preferably, from the endframe 7; This construction willpermit of a slight movement in the direction of the shaft 12, but willnot permit the member 54 to turn therewith.

\Vhen the current is off and the armature stationary, the clutch member51- is pushed outwardly against the disk 52 by means of a helical spring58, which is coiled about the shaft and is under compression when theclutch member 5a and the disk 52 are in position. W'hen the current issent through the magnet-coils 55, the member becomes magnetized andattracts the frame-piece 7 and the trunnion of the drum 9, so that it isdrawn toward them and away from the disk 52, thus compressing stillfurther the spring 58. This removes all friction between the member 54.and the disk 52, so that the shaft 12 can retate freely. \Vhen, however,the current is TOO ' rection.

cut off, the spring forces the said member against the disk, and as theformer is held from rotation the friction between the contactingsurfaces will be sufficient to bring the motor quickly to rest. It willbe. seen, therefore, that when the current is sent through the motor todrive the same the clutch member will be held away from contact with thedisk 52, so that the armature can rotate freely.

In order to avoid any possibility of a fall or a too rapid descent ofthe load by reason of the stoppage of the current or the breakage of anyof the driving parts, we place at some convenient and suitable point inthe train of gearing a safety lowering device,,

which will permit the load to descend only as the motor is positivelydriven in a reverse di- This device is shown in the drawings as appliedto the shaft 18. Fig. 4, being a detail sectional view thereof. Itconsists of three members 59, 60, and 61, which are keyed to rotate withthe shaft, but are capable of slight longitudinal movement thereon. Themember 59 is prevented from moving too far by a collar 62, which issecured to the shaft. The adjacent faces of the members 59, 60, and 61are provided with frictional surfaces, as indicated at 63, Fig. 4, whichare adapted to engage with inwardly-extending ribs 64 of ratchet-rings65. The ratchets on these rings are engaged by a detent-pawl 66, whichis supported from a cross-rod 67, so that the rings can turn in but onedirection, that being the direction in which the shaft 18 turns when aload is being hoisted. In case this shaft should turn backwardly,therefore, the ratchet-rings would be held, and if the friction betweenthe ribs 64 and the surfaces of the members 59, 60, and 61 is greatenough the shaft will be prevented from turning and the load will beheld suspended. The pinion 19,which is loosely mounted on the shaft 18,is provided on its face next the member 61 with a helix or cam shapedsurface, (indicated at 68,) and the said member is also provided with acorresponding surface engaging therewith. The pinion is prevented frommoving too far from the member 61 by a collar 69,which is secured to theshaft. Between the collars 62 and 69 there is room for mounting themembers 59, 60, and 61 and the pinion 19, provided the helical surfaces68 are fitted together. Let it be assumed that they are in the positionwith the collar in place and that the shaft 18, with the members 59, 60,and 61, are driven, so that their upper parts move toward the eye, asseen in Figs. 1 and 4. The pinion 19 will resist such movement becauseof its connection with the drum 9, which is lifting the load. Thispinion will therefore refuse to turn until the helical surfaces 68 camthemselves as far apart as the collars 62 and 69 will permit, when itmust also rotate with the shaft. This wedging action of the cams hasresulted in pressing the frictional surfaces 63 and the ribs 64 verytightly together, so that the ratchet-rings 65 are also compelled torotate, which the detcnt-pawl permits as long as they rotate in thisdirection. Now bearing in mind that the load on the drum is alwaystending to rotate the pinion backwardly, which presses the frictionmembers and the ratchet-rings tightly together, let the current beturned off of the motor or some of the gearing break. Immediately thefriction members and the ratchets will start back with the pinion 19;but the ratchets will at once be caught and held by the detent-pawl, andthe friction between them and the said members is so great that theshaft will be held and the load be prevented from descending, and theratchets and pawl will continue to hold the shaft 18 until it is drivenbackwardly by the motor itself, thus forcing the friction members andthe ribs 64 to slip. It will be understood that the heavier the loadthat is lifted the greater is the friction in the safety loweringdevice, and as the frictional surfaces are designed so as to check andhold any load that the motor can lift said load can only be lowered byreversing the motor, the speed of which is under perfect control.

Although we have thus far confined our description to the form of deviceshown in Figs. 1 to 5, in which an electric motor is employed fordriving the drum, we do not limit our invention to that kind of motor.In Figs. 6 and 7 we show a hoisting-drum, in which are mounted a numberof engine-cylinders 70, the pistons of which are connected through rods71 with cranks 72 on the main shaft 73, said shaft corresponding withthe motor-shaft 12, shown in the other views. The cranks are placed atangles with one another, so that when one is passing its dead-center oneor more of the others will be in operating position. Theengine-cylinders are trunnioned in brackets 75, which project from theinterior of the drum 9. Although different means may be employed forconducting the steam, compressed air, gas, or other driving agent to thevarious cylinders, we prefer to use a pipe 76, which is connectedthrough a swingjoint 77 with a tube-like opening 78 in the center of theshaft 73. Inside the drum this opening branches into radial openings 79,which extend to the outside of the shaft. Secured to the shaft so as tocover these openings is a collar 80, which is also provided with radialopenings 81, said openings being in register with those in the shaft.Pipes 82 and 83 connect the openings in the collar with the trunnions 74of the cylinders, through which the steam is admitted through valves 84,as is common in oscillating engines of this character.

As stated above, steam, compressed air, or gas may be employed fordriving these engines, or, if desired, explosive-engines may be usedinstead. It will be seen, therefore,

that we do not limit our invention to any particular form of drivingmeans, and when the general term motor is used in the claims it is to beunderstood as including any form of driving means, whether electricmotor, steamengine, or any other generating device whatever.

As shown in Fig. 3, the hoisting-drum extends parallel with the bridgeof the crane rather than perpendicularly therewith, as in the usualconstruction. This we regard as an important improvement, inasmuch asthe two strands of the supporting-cable prevent the load from swingingtransversely to its direction of motion as the crane is traveling alongits runways. \Vhen the path through which the load is moving is narrow,this becomes a valuable feature of our crane, as it prevents the loadfrom bumping into machines, &c., which stand at the sides of the path.

Having thus described our invention, what we claim as new, and desire tosecure by Letters Patent, is-

1. In a hoisting apparatus, frame-pieces, a drum trunnioned in saidframe-pieces, magmetic pole-pieces connected with said drum, an armaturemounted in the field of said polepieces and supported by the trunnionsof the drum, and gearing connecting said armature and drum.

' 2. In a hoisting apparatus, frame-pieces, a

drum trunnioned in said frame-pieces, magnetic polepieccs projectingfrom the inner surface of said drum, an armature mounted for rotationwithin the drum and between the pole-pieces, the shaft of said armaturebeing journaled in the trunnions of said drum, and gearing connectingsaid shaft with the drum to rotate the same.

3. In a hoisting device, framepieces, a hoisting-drum carrying magnetpolepieces trunnioned in said frame-pieces, a rotatable armature withinthe field of said pole-pieces, the shaft for which is journaled in thetrunnions of the same, and means for rotating said field-magnets in thesame direction as the armature in order to increase the speed of thelatter.

4. In a hoisting apparatus, a rotatable drum, a shaft passing throughsaid drum, a motor for turning said shaft, gearing connecting said shaftwith the drum, and means whereby the speed of the drum may be variedwithout changing the speed of the motor.

5. In a hoisting apparatus, a drum, magnetic pole-pieces connected withsaid drum, an armature rotatably mounted in the field of saidpole-pieces, gearing connecting said armature with the drum to rotatethe same, and means whereby the speed of the drum may be varied withoutchanging the speed of the motor.

6. In a hoisting a1')paratus, frame-pieces, a drum trunnioned in saidframe-pieces, magnetic pole-pieces projecting from the inner surface ofsaid drum, an armature mounted for rotation within the drum and betweenthe pole-pieces, the shaft of said armature being journaled in thetrunnions of said drum, gearing connecting said shaft with the drum torotate the same, and means whereby the speed of the drum may be variedwithout changing the speed of the motor.

7. In a hoisting apparatus, a drum, a shaft passing through said drum, amotor mounted in said drum for turning the shaft, a train of gearingconnecting said shaft and drum, and a safety lowering device interposedin said train.

8. In a hoisting apparatus, a drum, a shaft passing through said drum, amotor for turning the shaft, a train of gearing com'lecting the shaftand drum, a disk secured to said shaft, a clutch member non-rotatablymounted on said shaft but capable of slight longitudinal movementthereon, a spring for normally holding said clutch member in frictionalcontact with the disk, and means for moving the same out of contact whenit is desired to move the shaft.

In testimony whereof we aliix our signatures in the presence of twowitnesses.

VICTOR R. BR()\VNING. EARL H. BROVVNI NU.

IVitnesses:

S. E. FoU'rs, H. A. AUER.

